[Android]Check that ContextualSearchManager is not null before use

In order to disable the keyboard accessory within the contextual search
panel,the ManualFillingMediator calls isSearchPanelOpened() on the
ContextualSearchManager that it gets from the acivity. Since the
contextual search manager can be null, a check is required prior
to calling that method.

Bug: 887833
Change-Id: I85203cbb233a2ae7eec8a008ebd63c40bbd1a170
Reviewed-on: https://chromium-review.googlesource.com/1238473Reviewed-by: Rouslan Solomakhin <rouslan@chromium.org>
Commit-Queue: Ioana Pandele <ioanap@chromium.org>
Cr-Commit-Position: refs/heads/master@{#593616}

chrome/android/java/src/org/chromium/chrome/browser/autofill/keyboard_accessory/ManualFillingMediator.java

@@ -20,6 +20,7 @@ import org.chromium.chrome.browser.compositor.CompositorViewHolder;
 import org.chromium.chrome.browser.compositor.layouts.Layout;
 import org.chromium.chrome.browser.compositor.layouts.LayoutManager;
 import org.chromium.chrome.browser.compositor.layouts.SceneChangeObserver;
+import org.chromium.chrome.browser.contextualsearch.ContextualSearchManager;
 import org.chromium.chrome.browser.fullscreen.FullscreenOptions;
 import org.chromium.chrome.browser.tab.EmptyTabObserver;
 import org.chromium.chrome.browser.tab.Tab;
@@ -191,7 +192,11 @@ class ManualFillingMediator
         if (!mKeyboardAccessory.hasContents()) return; // Exit early to not affect the layout.
         if (isShowing) {
             // Don't open the accessory inside the contextual search panel.
-            if (mActivity.getContextualSearchManager().isSearchPanelOpened()) return;
+            ContextualSearchManager contextualSearchManager =
+                    mActivity.getContextualSearchManager();
+            if (contextualSearchManager != null && contextualSearchManager.isSearchPanelOpened()) {
+                return;
+            }
             mKeyboardAccessory.requestShowing();
             mActivity.getFullscreenManager().setBottomControlsHeight(calculateAccessoryBarHeight());
             mKeyboardAccessory.closeActiveTab();